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-rw-r--r--hw/milkymist-vgafb.c318
1 files changed, 318 insertions, 0 deletions
diff --git a/hw/milkymist-vgafb.c b/hw/milkymist-vgafb.c
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+
+/*
+ * QEMU model of the Milkymist VGA framebuffer.
+ *
+ * Copyright (c) 2010 Michael Walle <michael@walle.cc>
+ *
+ * This library is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2 of the License, or (at your option) any later version.
+ *
+ * This library is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with this library; if not, see <http://www.gnu.org/licenses/>.
+ *
+ *
+ * Specification available at:
+ * http://www.milkymist.org/socdoc/vgafb.pdf
+ */
+
+#include "hw.h"
+#include "sysbus.h"
+#include "trace.h"
+#include "console.h"
+#include "framebuffer.h"
+#include "pixel_ops.h"
+#include "qemu-error.h"
+
+#define BITS 8
+#include "milkymist-vgafb_template.h"
+#define BITS 15
+#include "milkymist-vgafb_template.h"
+#define BITS 16
+#include "milkymist-vgafb_template.h"
+#define BITS 24
+#include "milkymist-vgafb_template.h"
+#define BITS 32
+#include "milkymist-vgafb_template.h"
+
+enum {
+ R_CTRL = 0,
+ R_HRES,
+ R_HSYNC_START,
+ R_HSYNC_END,
+ R_HSCAN,
+ R_VRES,
+ R_VSYNC_START,
+ R_VSYNC_END,
+ R_VSCAN,
+ R_BASEADDRESS,
+ R_BASEADDRESS_ACT,
+ R_BURST_COUNT,
+ R_SOURCE_CLOCK,
+ R_MAX
+};
+
+enum {
+ CTRL_RESET = (1<<0),
+};
+
+struct MilkymistVgafbState {
+ SysBusDevice busdev;
+ DisplayState *ds;
+
+ int invalidate;
+ uint32_t fb_offset;
+ uint32_t fb_mask;
+
+ uint32_t regs[R_MAX];
+};
+typedef struct MilkymistVgafbState MilkymistVgafbState;
+
+static int vgafb_enabled(MilkymistVgafbState *s)
+{
+ return !(s->regs[R_CTRL] & CTRL_RESET);
+}
+
+static void vgafb_update_display(void *opaque)
+{
+ MilkymistVgafbState *s = opaque;
+ int first = 0;
+ int last = 0;
+ drawfn fn;
+
+ if (!vgafb_enabled(s)) {
+ return;
+ }
+
+ int dest_width = s->regs[R_HRES];
+
+ switch (ds_get_bits_per_pixel(s->ds)) {
+ case 0:
+ return;
+ case 8:
+ fn = draw_line_8;
+ break;
+ case 15:
+ fn = draw_line_15;
+ dest_width *= 2;
+ break;
+ case 16:
+ fn = draw_line_16;
+ dest_width *= 2;
+ break;
+ case 24:
+ fn = draw_line_24;
+ dest_width *= 3;
+ break;
+ case 32:
+ fn = draw_line_32;
+ dest_width *= 4;
+ break;
+ default:
+ hw_error("milkymist_vgafb: bad color depth\n");
+ break;
+ }
+
+ framebuffer_update_display(s->ds,
+ s->regs[R_BASEADDRESS] + s->fb_offset,
+ s->regs[R_HRES],
+ s->regs[R_VRES],
+ s->regs[R_HRES] * 2,
+ dest_width,
+ 0,
+ s->invalidate,
+ fn,
+ NULL,
+ &first, &last);
+
+ if (first >= 0) {
+ dpy_update(s->ds, 0, first, s->regs[R_HRES], last - first + 1);
+ }
+ s->invalidate = 0;
+}
+
+static void vgafb_invalidate_display(void *opaque)
+{
+ MilkymistVgafbState *s = opaque;
+ s->invalidate = 1;
+}
+
+static void vgafb_resize(MilkymistVgafbState *s)
+{
+ if (!vgafb_enabled(s)) {
+ return;
+ }
+
+ qemu_console_resize(s->ds, s->regs[R_HRES], s->regs[R_VRES]);
+ s->invalidate = 1;
+}
+
+static uint32_t vgafb_read(void *opaque, target_phys_addr_t addr)
+{
+ MilkymistVgafbState *s = opaque;
+ uint32_t r = 0;
+
+ addr >>= 2;
+ switch (addr) {
+ case R_CTRL:
+ case R_HRES:
+ case R_HSYNC_START:
+ case R_HSYNC_END:
+ case R_HSCAN:
+ case R_VRES:
+ case R_VSYNC_START:
+ case R_VSYNC_END:
+ case R_VSCAN:
+ case R_BASEADDRESS:
+ case R_BURST_COUNT:
+ case R_SOURCE_CLOCK:
+ r = s->regs[addr];
+ break;
+ case R_BASEADDRESS_ACT:
+ r = s->regs[R_BASEADDRESS];
+ break;
+
+ default:
+ error_report("milkymist_vgafb: read access to unknown register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ }
+
+ trace_milkymist_vgafb_memory_read(addr << 2, r);
+
+ return r;
+}
+
+static void
+vgafb_write(void *opaque, target_phys_addr_t addr, uint32_t value)
+{
+ MilkymistVgafbState *s = opaque;
+
+ trace_milkymist_vgafb_memory_write(addr, value);
+
+ addr >>= 2;
+ switch (addr) {
+ case R_CTRL:
+ case R_HSYNC_START:
+ case R_HSYNC_END:
+ case R_HSCAN:
+ case R_VSYNC_START:
+ case R_VSYNC_END:
+ case R_VSCAN:
+ case R_BURST_COUNT:
+ case R_SOURCE_CLOCK:
+ s->regs[addr] = value;
+ break;
+ case R_BASEADDRESS:
+ if (value & 0x1f) {
+ error_report("milkymist_vgafb: framebuffer base address have to "
+ "be 32 byte aligned");
+ break;
+ }
+ s->regs[addr] = value & s->fb_mask;
+ s->invalidate = 1;
+ break;
+ case R_HRES:
+ case R_VRES:
+ s->regs[addr] = value;
+ vgafb_resize(s);
+ break;
+ case R_BASEADDRESS_ACT:
+ error_report("milkymist_vgafb: write to read-only register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+
+ default:
+ error_report("milkymist_vgafb: write access to unknown register 0x"
+ TARGET_FMT_plx, addr << 2);
+ break;
+ }
+}
+
+static CPUReadMemoryFunc * const vgafb_read_fn[] = {
+ NULL,
+ NULL,
+ &vgafb_read
+};
+
+static CPUWriteMemoryFunc * const vgafb_write_fn[] = {
+ NULL,
+ NULL,
+ &vgafb_write
+};
+
+static void milkymist_vgafb_reset(DeviceState *d)
+{
+ MilkymistVgafbState *s = container_of(d, MilkymistVgafbState, busdev.qdev);
+ int i;
+
+ for (i = 0; i < R_MAX; i++) {
+ s->regs[i] = 0;
+ }
+
+ /* defaults */
+ s->regs[R_CTRL] = CTRL_RESET;
+ s->regs[R_HRES] = 640;
+ s->regs[R_VRES] = 480;
+ s->regs[R_BASEADDRESS] = 0;
+}
+
+static int milkymist_vgafb_init(SysBusDevice *dev)
+{
+ MilkymistVgafbState *s = FROM_SYSBUS(typeof(*s), dev);
+ int vgafb_regs;
+
+ vgafb_regs = cpu_register_io_memory(vgafb_read_fn, vgafb_write_fn, s,
+ DEVICE_NATIVE_ENDIAN);
+ sysbus_init_mmio(dev, R_MAX * 4, vgafb_regs);
+
+ s->ds = graphic_console_init(vgafb_update_display,
+ vgafb_invalidate_display,
+ NULL, NULL, s);
+
+ return 0;
+}
+
+static int vgafb_post_load(void *opaque, int version_id)
+{
+ vgafb_invalidate_display(opaque);
+ return 0;
+}
+
+static const VMStateDescription vmstate_milkymist_vgafb = {
+ .name = "milkymist-vgafb",
+ .version_id = 1,
+ .minimum_version_id = 1,
+ .minimum_version_id_old = 1,
+ .post_load = vgafb_post_load,
+ .fields = (VMStateField[]) {
+ VMSTATE_UINT32_ARRAY(regs, MilkymistVgafbState, R_MAX),
+ VMSTATE_END_OF_LIST()
+ }
+};
+
+static SysBusDeviceInfo milkymist_vgafb_info = {
+ .init = milkymist_vgafb_init,
+ .qdev.name = "milkymist-vgafb",
+ .qdev.size = sizeof(MilkymistVgafbState),
+ .qdev.vmsd = &vmstate_milkymist_vgafb,
+ .qdev.reset = milkymist_vgafb_reset,
+ .qdev.props = (Property[]) {
+ DEFINE_PROP_UINT32("fb_offset", MilkymistVgafbState, fb_offset, 0x0),
+ DEFINE_PROP_UINT32("fb_mask", MilkymistVgafbState, fb_mask, 0xffffffff),
+ DEFINE_PROP_END_OF_LIST(),
+ }
+};
+
+static void milkymist_vgafb_register(void)
+{
+ sysbus_register_withprop(&milkymist_vgafb_info);
+}
+
+device_init(milkymist_vgafb_register)
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